richardson



(No Model.)

(J. H. RICHARDSON. REGULATING APPARATUS FOR ELECTRIC MOTORS.

,750. Patented Aug. 22,1393.

HGQZ.

INVENTOR WITNESSES 1 Darren STATES PATENT OFFICE.

CHARLES H. RICHARDSON, OF PHILADELPHIA, PENNSYLVANIA, ASSIGNOR TO THE S.S. WVHITE DENTAL MANUFACTURING COMPANY, OF SAME PLACE.

REGULATING APPARATUS FOR ELECTRIC MOTORS.

SPECIFICATION forming part of Letters Patent No. 503,750, dated August22, 1893.

Application filed April 27,1893. Berial No. 472,111. (No model.)

To all whom it may concern.-

Be it known that 1, CHARLES H. RICHARD- SON, of the city and county ofPhiladelphia and State of Pennsylvania, have invented a certain new anduseful Improvement in RegulatingApparat-us for Electric Motors, of whichthe following is a specification.

As is well known the usual method of slowing the speed of an electricmotor is to insert resistance in series with the armature of the motor.In my application, Serial No. 458,497, filed January 16, 1893, there isshown means for reducing speed while retaining a strong pull or torque,applicable to that form of motor known as a motor-generator, or agenerator dll-VGll by a motor, which both consist of an electricgenerator driven by an electric motor; and my improvement in means forreducing speed consisted of a resistance in series with the motor forthe first reduction in speed,and a variable resistance through which acircuit between the brushes of the generator was made. This circuitallowed a current to pass through the generator which required power andstill further slowed it down, with a strong pull, as fully described inmy said application.

The object of my present invention is to provide sure means for makingthe proper connections to throw in the necessary resistance to varyspeed at the proper times, as if improperly made the motor might bedamaged.

My improvements, hereinafter specifically claimed, involve theemployment of a number of resistances of the proper ohms to give thedesired reduction in speed, and a switch lever making contact withcertain contact points properly connected to the resistances to connectthem in appropriate manner to attain the desired result.

In the accompanying drawings which show my improvement as suitablyembodied, Figure 1 is a diagrammatic View of my invention as applied toa series motor and generator,

and Fig. 2 is a similar view of my invention as modified to adapt it tobe applied to a shunt motor and generator.

Referring to Fig. 1, it will be seen that one main line L enters themotor and after passend of a switch lever D which is provided with anon-conducting or insulating section E, while the other end of thislever is passing over contacts 9 g g g and h. The contacts g g g g areconnected to resistances Z Z Zwhich at one end are connected to onebrush of the commutator of the generator 0 which is mechanically drivenby the motor. The other brush of the generator is connected to segmenth. Insulated rests m on for the switch lever in open circuit positionare provided. it is an insulated guide for one end of the switch leverduring times when the other end is passing over contacts (1 e e e.

The operation of the above described apparatus is as follows:-Withswitch lever D on rests m m as shown by dotted lines the circuit is openand the motor at rest. Upon moving the switch leverin the directionindicated by the arrow until it makes contact at one end with contact 6and at its opposite end with contacts g and h, the main current entersthrough L, D, cfff and d to the motor, and out to line L, thus startingthe motor. That part of the switch lever beyond the insulating section Ethereof connects contacts g and h which short circuits the generatorarmature, allows it to generate a current, and slows down the motor toslowest speed. As the switch lever is moved farther in the directionindicated by the arrow, and one of its ends passes over contacts 9 g gmore resistance is thrown into the circuit of the generator, decreasingcurrent in its armature and allowing the speed of the motor generator toincrease. After the lever passes point p that is, leaves contact h-thegenerator circuit is broken, all internal load is taken 0d the motor,and the speed depends solely on the resistances fff in the motorcircuit. A farther movement of the switch lever D in the same directionas before successively cuts out resistances fff until the last contactpoint (Z is reached, when the motor is directly connected to main linesand runs at highest speed.

In Fig. 2 a modification of the improvement to suit it to a shunt woundmotor is represented. Extra contact segments 3 s 3 connected byresistances t t are placed 10 make contact with one end of the switchlever. Contact 8 connects with motorfield a by conductor c; and as thelever when the motor is at rest projects beyond contact 0', on startingthe motor by manipulating the switch lever the field is charged first,then the motor is started, and the speed is regulated in the same way asby the apparatus shown by Fig. 1 until the switch lever passes to thefirst one of the contacts 8 s. The field charging current now passesthrough resistancezf which weakens it as well as the magnetic strengthof the field, which still. further increases the speed of the motor. Bymoving the switch to the last contact 3 additional resistancet isinserted in the field circuit, the field is still further weakened, andthe speed further increased. To keep the armature of the motor incircuit while the switch lever is moving over the contacts 8 s, thecontact plate (1 is elongated as indicated at (1 so that the lever whenon either of said contacts 3 s will also make connection with saidprolonged portion (2 of contact (I.

The number of resistancess may be varied according to the variations inspeed desired; and if the high speeds provided for by means of theseresistances are not required the prolonged portion (1' ot the contact (Zmay be omitted and this contact terminate at the point indicated bydotted line i By my improvements it will be seen that as the switchmechanism in the motor circuit, and the switch mechanism in thegenerator circuit are simultaneously operated damage to the apparatusfrom improper manipulation of the switch is rendered impossible; andthat the switch mechanism and manner of manipulating it are so simplethat any one may operate the apparatus.

Although I have described and prefer to use a single switch actuatinglever for operating simultaneously the switch mechanism in both themotor and the generator circuits, for varying speed as explained, I donot wish to be understood as confining my invention to the employment ofa singlelever, as in lieu thereof two levers so connected as to worktogether might be employed.

I claim as my invention The combination of the motor,the generatormechanically driven thereby, switch mechanism in themotor circuit,switch mechanism in the generator circuit, and the switch lever by whichsaid mechanisms are simultaneously operated, substantially as set forth.

In testiinony'whereof I have hereunto subscribed my name.

CHARLES H. RICHARDSON.

Vitnesses:

LEVI TEAL, R. DALE SPARHAWK.

